The present invention relates to a machine for compacting fuel assemblies, constituted by protective structures containing the fuel and carrying caps at their ends, and for separating the caps from the structures.
During the shearing of dismantled fuel assemblies, it is often necessary to carry out the prior shaping and tightening of the protective structures of the fuel. In addition, the caps equipping in most cases fuel assemblies, in order to permit their handling or placing in reactors, must usually be separated from the protective structures before dissolving the fuel in nitric acid. At present, the assemblies are compacted and the caps separated by means of two different machines.
Thus, a first known procedure consists of separating the caps in a first machine involving a mechanical process, such as sawing, following with the compacting of the protective structures in a second machine, and finally the shearing of these structures into portions of limited length in a third machine, in order to permit the dissolving of the fuel in acid. This first procedure suffers from the disadvantage of being particularly onerous, because it requires three different machines for carrying out the three operations which have to be performed on the assemblies. This large number of machines increases the risk of failure of one of them, with the result of a productivity drop in the production line.
A second known procedure consists of compacting the fuel assemblies in a first machine, then shearing the protective structures and their separation from their caps in a second machine. Although this procedure only involves the use of two machines, it has a number of disadvantages. Firstly, it makes it necessary to equip the shears with complementary stations, such as a cap slide leading to an increase in the complexity of these machines. Moreover, the separation of the caps within the shears has the important disadvantage that the caps come into contact with the fissile material, so that they must be looked upon as .alpha. waste. This significantly increases the quantity of waste of this type which, as is known, involves very stringent handling and conditioning precautions.
Finally, no matter what the procedure used, the hitherto known compacting machines use a side clamping means, which locally deforms the components of the assembly. One of the risks resulting from this deformation is the fracture of the structures surrounding the fuel, due to excessive stretching of the deformed parts (exceeding the breaking load in tension).